In recent years, with the development and popularization of network technology and sensor technology, attention has been given to stream processing which is designed to process, in real time, large amount of stream data that are generated every moment.
For example, stream processing is used to aggregate instantaneous sales by receiving point of sale (POS) system data as stream data and to partition the received POS data into multiple groups. Furthermore, stream processing is used to aggregate instantaneous traffic volumes by receiving probe traffic information as stream data and to partition the received probe traffic information into multiple groups.
A known technology is used for stream processing, in which stream data are accumulated as records, and, if an instruction is received from a user, the accumulated records are partitioned. For example, stream data that do not contain an item, such as a sequence number, used to specify a record are sorted by using a specific item in the stream data and are then accumulated. The sequence number mentioned here is the number sequentially allocated to, for example, data from the top or from the end. Then, if a partition request is received from a user, the records that are sorted and accumulated are partitioned and output to the user.
Patent Literature: Japanese Laid-open Patent Publication No. 2007-011784